Bleeding Disorders

Thrombosis in VWF and Hemophilia

From Crystal Wilson: Hello George, I am writing to ask if you could help me to understand how, on rare occasions, patients suffering from bleeding disorders such as von Willebrand disease or hemophilia have suffered from hypercoagulable episodes such as pulmonary emboli or deep vein thrombosis. Thanks. Hello, Crystal, I sent your question to several […]

Bleeding Disorders

Chromogenic Factor IX Assay

The Precision BioLogic Inc. and the Affinity Biologicals, Inc. research team presented a poster describing the recovery characteristics of a new chromogenic factor IX assay at the July 17–21, 2021 meeting of the International Society on Thrombosis and Haemostasis. The poster is now available for your download: Tara Quinton, Rachel Clarke, John Fraser, Karen M. […]

Bleeding Disorders

August, 2021 Quick Question

Our August, 2021 Quick Question is “Which factor deficiency causes the smallest risk of bleeding?” Please answer at your convenience. This question may lead us to a discussion of the current research developments for safer anticoagulant preparations.

Bleeding Disorders

Chromogenic Factor IX Assay

Click here to see the Precision BioLogic research team’s latest poster, Quinton T, Clarke R, Fraser J, Black KM, Sadeghi-Khomami A. Validation of a New Kit for the Quantitative Determination of Chromogenic Factor IX Activity. This poster was presented at the July 17–21 ISTH meeting.

Bleeding Disorders

Platelet Function Testing

There is a comprehensive summary in the June, 2021 CAP Today by Amy Carpenter Aquino entitled, “Puzzling Out Platelet Function Disorders,” [click] featuring Catherine PM Hayward, MD, PhD, of McMaster University, champion of the time-honored light transmittance aggregometry [LTA} approach to platelet testing.

Bleeding Disorders

New Fundamentals in Hemostasis

Thanks to my colleague Carlo Ledesma, MS, SH(ASCP)QLS, MT(ASCPi), MT(AMT) for pointing me to an in-depth hemostasis review, Versteeg HH, Heemskerk JWM, Levi M, Reitsma PH. New Fundamentals in Hemostasis. Physiol Rev 2013;93:327–58. This is a valuable teaching resource that helps elucidate the cell-based hemostasis model.

Arterial Thrombosis

Acquired von Willebrand Syndrome [AVWS]

From Dr. Jasmina Aluwahlia, regarding detection of anti Von Willebrand factor antibodies. “Hello George, how does one screen for anti-VWF antibodies in a suspected case of acquired AVWS? We assay the VWF:Ag and VWF:GPIbR on a automated coagulometer. The VWF:GPIbR is based on a latex immunoassay. Is there any protocol that can be used on […]

Bleeding Disorders

Mixing Study Limits

From a participant: Can you please help me to understand how to make a cut off value for a correction study so that above this value is corrected and below is not? Please provide an example. Thank you. Hello, and thank you for your question. Please click this link to our educational module, “Improving Acute […]

Bleeding Disorders

Extended Half-life FVIII & FIX and the PTT

From Carolyn McCarville: Hi George, My small laboratory is trying to figure out the best management of coag samples from patients receiving extended half life factor replacement products. We understand that many of the one stage clotting factor assays are inaccurate for the wealth of these products. One thing that we cannot get a straight […]

Bleeding Disorders

March 2021 Quick Question Response

Our March, 2021 Quick Question was a case study that netted 49 votes. A 2 YO experiences frequent joint bleeds. PT: 22s; PTT: 29s; fibrinogen 280 mg/dL. What do you do next? Assay factors VIII, IX, and XI. 10% [5] Assay factors II, V, and X, 14% [7] Assay factor VII, 70% [34, correct] Assay […]

Bleeding Disorders

Load more

George Fritsma is a medical laboratory scientist, educator, and author. George is a member of the International Society on Thrombosis and Hemostasis, the International Society for Laboratory Hematology, and the American Society for Clinical Laboratory Science.

Cheat Sheets from George

Quick Question